Nanostructured pyrochlore La 2 Zr 2 O 7 fibers were fabricated by a sol–gel combined electrospinning technique with Zr(OAc) 4 and LaCl 3 ·7H 2 O as reagents, silica sol as doping reagent and PVP as spinnable aid. The fibers had dense texture with uniform diameter of ca.2.5μm and smooth surface. Scanning electron microscope observation indicated that the fibers were composed of the La 2 Zr 2 O 7 grains with size of about 50–100nm. The formation of the La 2 Zr 2 O 7 fibers was tracked and the effect of the silica content was investigated. Further characterization revealed the low thermal conductivity (0.05415W/m·K) of the fiber at room temperature, which showed potential application as high-temperature insulation materials.